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/*
* timb_dma.c timberdale FPGA DMA driver
* Copyright (c) 2010 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* Supports:
* Timberdale FPGA DMA engine
*/
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/timb_dma.h>
#define DRIVER_NAME "timb-dma"
/* Global DMA registers */
#define TIMBDMA_ACR 0x34
#define TIMBDMA_32BIT_ADDR 0x01
#define TIMBDMA_ISR 0x080000
#define TIMBDMA_IPR 0x080004
#define TIMBDMA_IER 0x080008
/* Channel specific registers */
/* RX instances base addresses are 0x00, 0x40, 0x80 ...
* TX instances base addresses are 0x18, 0x58, 0x98 ...
*/
#define TIMBDMA_INSTANCE_OFFSET 0x40
#define TIMBDMA_INSTANCE_TX_OFFSET 0x18
/* RX registers, relative the instance base */
#define TIMBDMA_OFFS_RX_DHAR 0x00
#define TIMBDMA_OFFS_RX_DLAR 0x04
#define TIMBDMA_OFFS_RX_LR 0x0C
#define TIMBDMA_OFFS_RX_BLR 0x10
#define TIMBDMA_OFFS_RX_ER 0x14
#define TIMBDMA_RX_EN 0x01
/* bytes per Row, video specific register
* which is placed after the TX registers...
*/
#define TIMBDMA_OFFS_RX_BPRR 0x30
/* TX registers, relative the instance base */
#define TIMBDMA_OFFS_TX_DHAR 0x00
#define TIMBDMA_OFFS_TX_DLAR 0x04
#define TIMBDMA_OFFS_TX_BLR 0x0C
#define TIMBDMA_OFFS_TX_LR 0x14
#define TIMB_DMA_DESC_SIZE 8
struct timb_dma_desc {
struct list_head desc_node;
struct dma_async_tx_descriptor txd;
u8 *desc_list;
unsigned int desc_list_len;
bool interrupt;
};
struct timb_dma_chan {
struct dma_chan chan;
void __iomem *membase;
spinlock_t lock; /* Used to protect data structures,
especially the lists and descriptors,
from races between the tasklet and calls
from above */
dma_cookie_t last_completed_cookie;
bool ongoing;
struct list_head active_list;
struct list_head queue;
struct list_head free_list;
unsigned int bytes_per_line;
enum dma_data_direction direction;
unsigned int descs; /* Descriptors to allocate */
unsigned int desc_elems; /* number of elems per descriptor */
};
struct timb_dma {
struct dma_device dma;
void __iomem *membase;
struct tasklet_struct tasklet;
struct timb_dma_chan channels[0];
};
static struct device *chan2dev(struct dma_chan *chan)
{
return &chan->dev->device;
}
static struct device *chan2dmadev(struct dma_chan *chan)
{
return chan2dev(chan)->parent->parent;
}
static struct timb_dma *tdchantotd(struct timb_dma_chan *td_chan)
{
int id = td_chan->chan.chan_id;
return (struct timb_dma *)((u8 *)td_chan -
id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
}
/* Must be called with the spinlock held */
static void __td_enable_chan_irq(struct timb_dma_chan *td_chan)
{
int id = td_chan->chan.chan_id;
struct timb_dma *td = tdchantotd(td_chan);
u32 ier;
/* enable interrupt for this channel */
ier = ioread32(td->membase + TIMBDMA_IER);
ier |= 1 << id;
dev_dbg(chan2dev(&td_chan->chan), "Enabling irq: %d, IER: 0x%x\n", id,
ier);
iowrite32(ier, td->membase + TIMBDMA_IER);
}
/* Should be called with the spinlock held */
static bool __td_dma_done_ack(struct timb_dma_chan *td_chan)
{
int id = td_chan->chan.chan_id;
struct timb_dma *td = (struct timb_dma *)((u8 *)td_chan -
id * sizeof(struct timb_dma_chan) - sizeof(struct timb_dma));
u32 isr;
bool done = false;
dev_dbg(chan2dev(&td_chan->chan), "Checking irq: %d, td: %p\n", id, td);
isr = ioread32(td->membase + TIMBDMA_ISR) & (1 << id);
if (isr) {
iowrite32(isr, td->membase + TIMBDMA_ISR);
done = true;
}
return done;
}
static void __td_unmap_desc(struct timb_dma_chan *td_chan, const u8 *dma_desc,
bool single)
{
dma_addr_t addr;
int len;
addr = (dma_desc[7] << 24) | (dma_desc[6] << 16) | (dma_desc[5] << 8) |
dma_desc[4];
len = (dma_desc[3] << 8) | dma_desc[2];
if (single)
dma_unmap_single(chan2dev(&td_chan->chan), addr, len,
td_chan->direction);
else
dma_unmap_page(chan2dev(&td_chan->chan), addr, len,
td_chan->direction);
}
static void __td_unmap_descs(struct timb_dma_desc *td_desc, bool single)
{
struct timb_dma_chan *td_chan = container_of(td_desc->txd.chan,
struct timb_dma_chan, chan);
u8 *descs;
for (descs = td_desc->desc_list; ; descs += TIMB_DMA_DESC_SIZE) {
__td_unmap_desc(td_chan, descs, single);
if (descs[0] & 0x02)
break;
}
}
static int td_fill_desc(struct timb_dma_chan *td_chan, u8 *dma_desc,
struct scatterlist *sg, bool last)
{
if (sg_dma_len(sg) > USHRT_MAX) {
dev_err(chan2dev(&td_chan->chan), "Too big sg element\n");
return -EINVAL;
}
/* length must be word aligned */
if (sg_dma_len(sg) % sizeof(u32)) {
dev_err(chan2dev(&td_chan->chan), "Incorrect length: %d\n",
sg_dma_len(sg));
return -EINVAL;
}
dev_dbg(chan2dev(&td_chan->chan), "desc: %p, addr: 0x%llx\n",
dma_desc, (unsigned long long)sg_dma_address(sg));
dma_desc[7] = (sg_dma_address(sg) >> 24) & 0xff;
dma_desc[6] = (sg_dma_address(sg) >> 16) & 0xff;
dma_desc[5] = (sg_dma_address(sg) >> 8) & 0xff;
dma_desc[4] = (sg_dma_address(sg) >> 0) & 0xff;
dma_desc[3] = (sg_dma_len(sg) >> 8) & 0xff;
dma_desc[2] = (sg_dma_len(sg) >> 0) & 0xff;
dma_desc[1] = 0x00;
dma_desc[0] = 0x21 | (last ? 0x02 : 0); /* tran, valid */
return 0;
}
/* Must be called with the spinlock held */
static void __td_start_dma(struct timb_dma_chan *td_chan)
{
struct timb_dma_desc *td_desc;
if (td_chan->ongoing) {
dev_err(chan2dev(&td_chan->chan),
"Transfer already ongoing\n");
return;
}
td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
desc_node);
dev_dbg(chan2dev(&td_chan->chan),
"td_chan: %p, chan: %d, membase: %p\n",
td_chan, td_chan->chan.chan_id, td_chan->membase);
if (td_chan->direction == DMA_FROM_DEVICE) {
/* descriptor address */
iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_DHAR);
iowrite32(td_desc->txd.phys, td_chan->membase +
TIMBDMA_OFFS_RX_DLAR);
/* Bytes per line */
iowrite32(td_chan->bytes_per_line, td_chan->membase +
TIMBDMA_OFFS_RX_BPRR);
/* enable RX */
iowrite32(TIMBDMA_RX_EN, td_chan->membase + TIMBDMA_OFFS_RX_ER);
} else {
/* address high */
iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DHAR);
iowrite32(td_desc->txd.phys, td_chan->membase +
TIMBDMA_OFFS_TX_DLAR);
}
td_chan->ongoing = true;
if (td_desc->interrupt)
__td_enable_chan_irq(td_chan);
}
static void __td_finish(struct timb_dma_chan *td_chan)
{
dma_async_tx_callback callback;
void *param;
struct dma_async_tx_descriptor *txd;
struct timb_dma_desc *td_desc;
/* can happen if the descriptor is canceled */
if (list_empty(&td_chan->active_list))
return;
td_desc = list_entry(td_chan->active_list.next, struct timb_dma_desc,
desc_node);
txd = &td_desc->txd;
dev_dbg(chan2dev(&td_chan->chan), "descriptor %u complete\n",
txd->cookie);
/* make sure to stop the transfer */
if (td_chan->direction == DMA_FROM_DEVICE)
iowrite32(0, td_chan->membase + TIMBDMA_OFFS_RX_ER);
/* Currently no support for stopping DMA transfers
else
iowrite32(0, td_chan->membase + TIMBDMA_OFFS_TX_DLAR);
*/
td_chan->last_completed_cookie = txd->cookie;
td_chan->ongoing = false;
callback = txd->callback;
param = txd->callback_param;
list_move(&td_desc->desc_node, &td_chan->free_list);
if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP))
__td_unmap_descs(td_desc,
txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE);
/*
* The API requires that no submissions are done from a
* callback, so we don't need to drop the lock here
*/
if (callback)
callback(param);
}
static u32 __td_ier_mask(struct timb_dma *td)
{
int i;
u32 ret = 0;
for (i = 0; i < td->dma.chancnt; i++) {
struct timb_dma_chan *td_chan = td->channels + i;
if (td_chan->ongoing) {
struct timb_dma_desc *td_desc =
list_entry(td_chan->active_list.next,
struct timb_dma_desc, desc_node);
if (td_desc->interrupt)
ret |= 1 << i;
}
}
return ret;
}
static void __td_start_next(struct timb_dma_chan *td_chan)
{
struct timb_dma_desc *td_desc;
BUG_ON(list_empty(&td_chan->queue));
BUG_ON(td_chan->ongoing);
td_desc = list_entry(td_chan->queue.next, struct timb_dma_desc,
desc_node);
dev_dbg(chan2dev(&td_chan->chan), "%s: started %u\n",
__func__, td_desc->txd.cookie);
list_move(&td_desc->desc_node, &td_chan->active_list);
__td_start_dma(td_chan);
}
static dma_cookie_t td_tx_submit(struct dma_async_tx_descriptor *txd)
{
struct timb_dma_desc *td_desc = container_of(txd, struct timb_dma_desc,
txd);
struct timb_dma_chan *td_chan = container_of(txd->chan,
struct timb_dma_chan, chan);
dma_cookie_t cookie;
spin_lock_bh(&td_chan->lock);
cookie = txd->chan->cookie;
if (++cookie < 0)
cookie = 1;
txd->chan->cookie = cookie;
txd->cookie = cookie;
if (list_empty(&td_chan->active_list)) {
dev_dbg(chan2dev(txd->chan), "%s: started %u\n", __func__,
txd->cookie);
list_add_tail(&td_desc->desc_node, &td_chan->active_list);
__td_start_dma(td_chan);
} else {
dev_dbg(chan2dev(txd->chan), "tx_submit: queued %u\n",
txd->cookie);
list_add_tail(&td_desc->desc_node, &td_chan->queue);
}
spin_unlock_bh(&td_chan->lock);
return cookie;
}
static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
{
struct dma_chan *chan = &td_chan->chan;
struct timb_dma_desc *td_desc;
int err;
td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
if (!td_desc) {
dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
goto out;
}
td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
td_desc->desc_list = kzalloc(td_desc->desc_list_len, GFP_KERNEL);
if (!td_desc->desc_list) {
dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
goto err;
}
dma_async_tx_descriptor_init(&td_desc->txd, chan);
td_desc->txd.tx_submit = td_tx_submit;
td_desc->txd.flags = DMA_CTRL_ACK;
td_desc->txd.phys = dma_map_single(chan2dmadev(chan),
td_desc->desc_list, td_desc->desc_list_len, DMA_TO_DEVICE);
err = dma_mapping_error(chan2dmadev(chan), td_desc->txd.phys);
if (err) {
dev_err(chan2dev(chan), "DMA mapping error: %d\n", err);
goto err;
}
return td_desc;
err:
kfree(td_desc->desc_list);
kfree(td_desc);
out:
return NULL;
}
static void td_free_desc(struct timb_dma_desc *td_desc)
{
dev_dbg(chan2dev(td_desc->txd.chan), "Freeing desc: %p\n", td_desc);
dma_unmap_single(chan2dmadev(td_desc->txd.chan), td_desc->txd.phys,
td_desc->desc_list_len, DMA_TO_DEVICE);
kfree(td_desc->desc_list);
kfree(td_desc);
}
static void td_desc_put(struct timb_dma_chan *td_chan,
struct timb_dma_desc *td_desc)
{
dev_dbg(chan2dev(&td_chan->chan), "Putting desc: %p\n", td_desc);
spin_lock_bh(&td_chan->lock);
list_add(&td_desc->desc_node, &td_chan->free_list);
spin_unlock_bh(&td_chan->lock);
}
static struct timb_dma_desc *td_desc_get(struct timb_dma_chan *td_chan)
{
struct timb_dma_desc *td_desc, *_td_desc;
struct timb_dma_desc *ret = NULL;
spin_lock_bh(&td_chan->lock);
list_for_each_entry_safe(td_desc, _td_desc, &td_chan->free_list,
desc_node) {
if (async_tx_test_ack(&td_desc->txd)) {
list_del(&td_desc->desc_node);
ret = td_desc;
break;
}
dev_dbg(chan2dev(&td_chan->chan), "desc %p not ACKed\n",
td_desc);
}
spin_unlock_bh(&td_chan->lock);
return ret;
}
static int td_alloc_chan_resources(struct dma_chan *chan)
{
struct timb_dma_chan *td_chan =
container_of(chan, struct timb_dma_chan, chan);
int i;
dev_dbg(chan2dev(chan), "%s: entry\n", __func__);
BUG_ON(!list_empty(&td_chan->free_list));
for (i = 0; i < td_chan->descs; i++) {
struct timb_dma_desc *td_desc = td_alloc_init_desc(td_chan);
if (!td_desc) {
if (i)
break;
else {
dev_err(chan2dev(chan),
"Couldnt allocate any descriptors\n");
return -ENOMEM;
}
}
td_desc_put(td_chan, td_desc);
}
spin_lock_bh(&td_chan->lock);
td_chan->last_completed_cookie = 1;
chan->cookie = 1;
spin_unlock_bh(&td_chan->lock);
return 0;
}
static void td_free_chan_resources(struct dma_chan *chan)
{
struct timb_dma_chan *td_chan =
container_of(chan, struct timb_dma_chan, chan);
struct timb_dma_desc *td_desc, *_td_desc;
LIST_HEAD(list);
dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
/* check that all descriptors are free */
BUG_ON(!list_empty(&td_chan->active_list));
BUG_ON(!list_empty(&td_chan->queue));
spin_lock_bh(&td_chan->lock);
list_splice_init(&td_chan->free_list, &list);
spin_unlock_bh(&td_chan->lock);
list_for_each_entry_safe(td_desc, _td_desc, &list, desc_node) {
dev_dbg(chan2dev(chan), "%s: Freeing desc: %p\n", __func__,
td_desc);
td_free_desc(td_desc);
}
}
static enum dma_status td_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct timb_dma_chan *td_chan =
container_of(chan, struct timb_dma_chan, chan);
dma_cookie_t last_used;
dma_cookie_t last_complete;
int ret;
dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
last_complete = td_chan->last_completed_cookie;
last_used = chan->cookie;
ret = dma_async_is_complete(cookie, last_complete, last_used);
dma_set_tx_state(txstate, last_complete, last_used, 0);
dev_dbg(chan2dev(chan),
"%s: exit, ret: %d, last_complete: %d, last_used: %d\n",
__func__, ret, last_complete, last_used);
return ret;
}
static void td_issue_pending(struct dma_chan *chan)
{
struct timb_dma_chan *td_chan =
container_of(chan, struct timb_dma_chan, chan);
dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
spin_lock_bh(&td_chan->lock);
if (!list_empty(&td_chan->active_list))
/* transfer ongoing */
if (__td_dma_done_ack(td_chan))
__td_finish(td_chan);
if (list_empty(&td_chan->active_list) && !list_empty(&td_chan->queue))
__td_start_next(td_chan);
spin_unlock_bh(&td_chan->lock);
}
static struct dma_async_tx_descriptor *td_prep_slave_sg(struct dma_chan *chan,
struct scatterlist *sgl, unsigned int sg_len,
enum dma_data_direction direction, unsigned long flags)
{
struct timb_dma_chan *td_chan =
container_of(chan, struct timb_dma_chan, chan);
struct timb_dma_desc *td_desc;
struct scatterlist *sg;
unsigned int i;
unsigned int desc_usage = 0;
if (!sgl || !sg_len) {
dev_err(chan2dev(chan), "%s: No SG list\n", __func__);
return NULL;
}
/* even channels are for RX, odd for TX */
if (td_chan->direction != direction) {
dev_err(chan2dev(chan),
"Requesting channel in wrong direction\n");
return NULL;
}
td_desc = td_desc_get(td_chan);
if (!td_desc) {
dev_err(chan2dev(chan), "Not enough descriptors available\n");
return NULL;
}
td_desc->interrupt = (flags & DMA_PREP_INTERRUPT) != 0;
for_each_sg(sgl, sg, sg_len, i) {
int err;
if (desc_usage > td_desc->desc_list_len) {
dev_err(chan2dev(chan), "No descriptor space\n");
return NULL;
}
err = td_fill_desc(td_chan, td_desc->desc_list + desc_usage, sg,
i == (sg_len - 1));
if (err) {
dev_err(chan2dev(chan), "Failed to update desc: %d\n",
err);
td_desc_put(td_chan, td_desc);
return NULL;
}
desc_usage += TIMB_DMA_DESC_SIZE;
}
dma_sync_single_for_device(chan2dmadev(chan), td_desc->txd.phys,
td_desc->desc_list_len, DMA_TO_DEVICE);
return &td_desc->txd;
}
static int td_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct timb_dma_chan *td_chan =
container_of(chan, struct timb_dma_chan, chan);
struct timb_dma_desc *td_desc, *_td_desc;
dev_dbg(chan2dev(chan), "%s: Entry\n", __func__);
if (cmd != DMA_TERMINATE_ALL)
return -ENXIO;
/* first the easy part, put the queue into the free list */
spin_lock_bh(&td_chan->lock);
list_for_each_entry_safe(td_desc, _td_desc, &td_chan->queue,
desc_node)
list_move(&td_desc->desc_node, &td_chan->free_list);
/* now tear down the running */
__td_finish(td_chan);
spin_unlock_bh(&td_chan->lock);
return 0;
}
static void td_tasklet(unsigned long data)
{
struct timb_dma *td = (struct timb_dma *)data;
u32 isr;
u32 ipr;
u32 ier;
int i;
isr = ioread32(td->membase + TIMBDMA_ISR);
ipr = isr & __td_ier_mask(td);
/* ack the interrupts */
iowrite32(ipr, td->membase + TIMBDMA_ISR);
for (i = 0; i < td->dma.chancnt; i++)
if (ipr & (1 << i)) {
struct timb_dma_chan *td_chan = td->channels + i;
spin_lock(&td_chan->lock);
__td_finish(td_chan);
if (!list_empty(&td_chan->queue))
__td_start_next(td_chan);
spin_unlock(&td_chan->lock);
}
ier = __td_ier_mask(td);
iowrite32(ier, td->membase + TIMBDMA_IER);
}
static irqreturn_t td_irq(int irq, void *devid)
{
struct timb_dma *td = devid;
u32 ipr = ioread32(td->membase + TIMBDMA_IPR);
if (ipr) {
/* disable interrupts, will be re-enabled in tasklet */
iowrite32(0, td->membase + TIMBDMA_IER);
tasklet_schedule(&td->tasklet);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
static int __devinit td_probe(struct platform_device *pdev)
{
struct timb_dma_platform_data *pdata = pdev->dev.platform_data;
struct timb_dma *td;
struct resource *iomem;
int irq;
int err;
int i;
if (!pdata) {
dev_err(&pdev->dev, "No platform data\n");
return -EINVAL;
}
iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!iomem)
return -EINVAL;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
if (!request_mem_region(iomem->start, resource_size(iomem),
DRIVER_NAME))
return -EBUSY;
td = kzalloc(sizeof(struct timb_dma) +
sizeof(struct timb_dma_chan) * pdata->nr_channels, GFP_KERNEL);
if (!td) {
err = -ENOMEM;
goto err_release_region;
}
dev_dbg(&pdev->dev, "Allocated TD: %p\n", td);
td->membase = ioremap(iomem->start, resource_size(iomem));
if (!td->membase) {
dev_err(&pdev->dev, "Failed to remap I/O memory\n");
err = -ENOMEM;
goto err_free_mem;
}
/* 32bit addressing */
iowrite32(TIMBDMA_32BIT_ADDR, td->membase + TIMBDMA_ACR);
/* disable and clear any interrupts */
iowrite32(0x0, td->membase + TIMBDMA_IER);
iowrite32(0xFFFFFFFF, td->membase + TIMBDMA_ISR);
tasklet_init(&td->tasklet, td_tasklet, (unsigned long)td);
err = request_irq(irq, td_irq, IRQF_SHARED, DRIVER_NAME, td);
if (err) {
dev_err(&pdev->dev, "Failed to request IRQ\n");
goto err_tasklet_kill;
}
td->dma.device_alloc_chan_resources = td_alloc_chan_resources;
td->dma.device_free_chan_resources = td_free_chan_resources;
td->dma.device_tx_status = td_tx_status;
td->dma.device_issue_pending = td_issue_pending;
dma_cap_set(DMA_SLAVE, td->dma.cap_mask);
dma_cap_set(DMA_PRIVATE, td->dma.cap_mask);
td->dma.device_prep_slave_sg = td_prep_slave_sg;
td->dma.device_control = td_control;
td->dma.dev = &pdev->dev;
INIT_LIST_HEAD(&td->dma.channels);
for (i = 0; i < pdata->nr_channels; i++, td->dma.chancnt++) {
struct timb_dma_chan *td_chan = &td->channels[i];
struct timb_dma_platform_data_channel *pchan =
pdata->channels + i;
/* even channels are RX, odd are TX */
if ((i % 2) == pchan->rx) {
dev_err(&pdev->dev, "Wrong channel configuration\n");
err = -EINVAL;
goto err_tasklet_kill;
}
td_chan->chan.device = &td->dma;
td_chan->chan.cookie = 1;
td_chan->chan.chan_id = i;
spin_lock_init(&td_chan->lock);
INIT_LIST_HEAD(&td_chan->active_list);
INIT_LIST_HEAD(&td_chan->queue);
INIT_LIST_HEAD(&td_chan->free_list);
td_chan->descs = pchan->descriptors;
td_chan->desc_elems = pchan->descriptor_elements;
td_chan->bytes_per_line = pchan->bytes_per_line;
td_chan->direction = pchan->rx ? DMA_FROM_DEVICE :
DMA_TO_DEVICE;
td_chan->membase = td->membase +
(i / 2) * TIMBDMA_INSTANCE_OFFSET +
(pchan->rx ? 0 : TIMBDMA_INSTANCE_TX_OFFSET);
dev_dbg(&pdev->dev, "Chan: %d, membase: %p\n",
i, td_chan->membase);
list_add_tail(&td_chan->chan.device_node, &td->dma.channels);
}
err = dma_async_device_register(&td->dma);
if (err) {
dev_err(&pdev->dev, "Failed to register async device\n");
goto err_free_irq;
}
platform_set_drvdata(pdev, td);
dev_dbg(&pdev->dev, "Probe result: %d\n", err);
return err;
err_free_irq:
free_irq(irq, td);
err_tasklet_kill:
tasklet_kill(&td->tasklet);
iounmap(td->membase);
err_free_mem:
kfree(td);
err_release_region:
release_mem_region(iomem->start, resource_size(iomem));
return err;
}
static int __devexit td_remove(struct platform_device *pdev)
{
struct timb_dma *td = platform_get_drvdata(pdev);
struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
int irq = platform_get_irq(pdev, 0);
dma_async_device_unregister(&td->dma);
free_irq(irq, td);
tasklet_kill(&td->tasklet);
iounmap(td->membase);
kfree(td);
release_mem_region(iomem->start, resource_size(iomem));
platform_set_drvdata(pdev, NULL);
dev_dbg(&pdev->dev, "Removed...\n");
return 0;
}
static struct platform_driver td_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.probe = td_probe,
.remove = __exit_p(td_remove),
};
static int __init td_init(void)
{
return platform_driver_register(&td_driver);
}
module_init(td_init);
static void __exit td_exit(void)
{
platform_driver_unregister(&td_driver);
}
module_exit(td_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Timberdale DMA controller driver");
MODULE_AUTHOR("Pelagicore AB <info@pelagicore.com>");
MODULE_ALIAS("platform:"DRIVER_NAME);